Method and apparatus for burning fuels



July 1, .1930. E. P.- WETMORE METHOD AND APPARATUS FOR BURNING FUELS Filed Oct. 25, 1924 l l l l lllllllll w m H WH W w l hl h H UH H I M I I I li |l m fi 4,. fi

IANVENTOR. Earl R. Wei/flake Patented July 1, 1930 NITED STATES PATENT OFFICE EARL P. WETMORE, OF CONCORD, MICHIGAN, ASSIGNOR TO THE ANOILCOAL BURNER 00., OF TOLEDO, OHIO, A CORPORATION OF DELAWARE METHOD AND APPARATUS FOR BURNING- FUELS Application filed OctOber 23, 1924. SerialNo. 745,308.

This invention relates to a method and apparatus for burning fuel, and, more particularly, to a burner adapted to form a readily combustible suspension in air of 5 fuels of a semi-fluid nature, such as the stifl pastes formed of solid and liquid fuels, or

I manner and reduced to a fine state of diviof other plastic fuels of similar nature.

Composite fuelsj of this type are commonly formed of minute particles of powdered 0 fuel, from which the ash content may have been removed to a greater or less extent, and

of a liquid fuel which surrounds the particles with a film or layer of oil and serves to unite the particles into a coherent paste, 5 of a nature intermediate that of the solid and liquid fuels of which it is composed, and having characteristics different from its constituents. These pastes, the stiffness of which is dependent on'the proportions and characteristics of their constituents, may be burned in the manner of solid fuels, but, because of the greater flexibility of control and ease of burning and consequently greater efficiencies in combustion, it is highly de- 5 sirable to burn them in the manner of fluid fuels by atomizing and diffusing them into a current of air in such a manner that they may be readily ignited and burned in a flame. Owing to the physical characteris- 0 tics of the composite fuels of the above mentioned types, they can not be handled in quite the same manner as liquid fuels, which flow readily, can be projected in jet form, and are readily broken up to a mist, nor in the manner ofpowdered fuels, which are already in a fine state of division and partly mixed with .air.

An object of my present invention is to provide a method and apparatus which will enable fuels of the above types and characteristics to be burned in a flame in a manner similar to fluid fuels.

Another object of the invention is to provide an apparatus by which the supply of air for supporting the combustion of the fuel may be readily controlled and adjusted to the requirements of the fuel.

A further object of the invention is to provide a fuel burner of the type indicated in which the supply of air to the fuel is automatically controlled or regulated in accordance with the requirements of the fuel.

A still further object of the invention is to provide an apparatus for burning fuels of the character indicated above in which the fuel is fed in a continuous and positive sion and suspension inair.

With these and other objects in view,

embodying a preferred form ofmy invention, and p Fig. 2 is a sectional view of the burner, taken on line 2-2 of'Fig. 1. V

In my present invention, the fuel is forced in a continuous manner through a supply passage-way by a suitable conveyor means, such asa screw conveyor, and is forced through a narrow orifice to issue as a thin sheet or ribbon. A jet of fluid, preferably air, is directed across the path of the sheet of fuel as it issues fromthe orifice and closely adjacent the outer face of the orifice so that the front, advancing edge of the sheet of fuel is sheared off and carried into the jet, the pressure of the air and velocity of the jet being sufficient to thoroughly disintegrate the body of fuel and carry the separated particles with their films of oil in a fine suspension in the current of air. The

issuing ribbon of fuel is preferably annular companying drawings, a supply of fuel is placed in a hopper mounted on, and opening downwardly into a horizontal conveyor tube 11, the adjacent end of the tube being closed by a plate 12 secured to the end of the tube Wall by screws 13. The fuel falling into the end portion; of the tube 11 from the hopper 10 is conveyed forwardly there in by means of a screw conveyor 14 rigidly mounted, on hollow supportingshaft or tube 15 one end of which projects-outwardly through, and is supported, in the plate 12. The shaft 15 and conveyor 1 4" maybe drivenby any suitable means, such as a worm 16 and gear 17 mounted onlthe end of: the shaft projecting on the outsideof the plate 12.

The opposite, inner'endoff the shaft 15' is sup-ported on aliXed" pipe 18, which extends through the shaft15 andis mounted at its inner end in a support 19, which is spaced, and supported froin the inner wall of the tube 11' by" radially projecting arms 20. The walls of the support 19*at the end of the conveyor 14: are flared outwardly at21 in a cone shape andextend to' within a short distance of'the inner faceof the wallof-the tube 11 leaving a small annular orifice 22. The fuel is forced by the conveyor 14: against the wall 21 of the support, 19,which acts as a mandrel or triblet, and through the annular orifice 22, issuing from the orifice as. a thin annular sheet.

Air under high pressure for disintegrating the fuel as it issues from the orifice 22, is supplied throughthe tube or pipe 18, which projects through the triblet or support 19 and extends forwardly.- thereof' for a short distance, The airfrom the pipe 18' is re ceived within a hollow cone 23 mounted on the projecting end portion of the pipe 18 and having a base wall 2&- spaced from the front face of' the triblet 19 to provide a narrow or thin space 25' therebetween. From the interior of the cone 23, the air is delivered, through openings 26 in the base wall 24 to the space 25 and then flows radially outwardly across the, path of the fuel issuing; through. the orifice,22,' The air is supplied; under-' a pressure sufficientlyhigh to disintegrate the sheet or wall of fuel as said aircuts ac-rossthepat h of thefuel and carry particles of disintegrated fuel with it, a pressure of ffrom fifty to one hundred and fifty pounds-being usually suflicient for this purpose.

The jet of air and commingled fuel is received" and deflected in an annular space 27 formedibetween the cone 23; and the inner face of a curved annular wall 28 mounted bymeans of a flange 29' on a flange 30 on the, front end of the tube; 1 1. The inner face o-fthe wall, 28 iscurved or bulged outwardly about theedge of the cone, which is-rounded" as at 31", togive the outwardly flowing jet I, of air a curved, expanding path, bringing itto the converging face of the cone 23 and thus giving it a forward velocity as it expands.

As the mixture of air and suspended fuel flows towards the tip of the cone 23, it enters a nozzle member 32 mounted by means of an outward flange on a flange 3d of the wall 28, said nozzle member 32 having a contracted or Venturi portion 35 into which theijet of air is directed on leaving thecone 23,,and, extending therefrom, an expanding mouth portion or combustion chamber 36 which is directed towards the mouth of a furnace in which the fuel'is to be burned. In passing: through the contracted portion of the venturi, a, slight vacuum is created into which an additional amount of air may be drawn through inlet openings 37? provided for this purpose, thus enabling an amount of; secondary air to be introduced when required to supply therequirements of the fuel; The amount of additional air thus drawn into the stream of" fuel may be regulated by means of a damper'ring 3S slidably mounted on a cylindrical surface 39*on the nozzle and adjustable towards or from'a conical' surface 10 to provide a variable inlet orifice for the S condary air.

The rate of supply of fuel is controlled'by the rate at which the screw conveyor 14: is driven from the worm 16' and gear 17, and

the supply of air. is'controlledin accordance with the drivingof theworm, Through this apparatus, therefore, the supply of f'ueLmay be, accurately controlled and maybe quickly adjusted to the demands of the furnace to. which the fuelissuppli'edi The disintegrating action of, the air jet is such that they minute particl'esof solid: fuel are separated from'each other and carried in suspensionby the air in such a condition that they may bereadily ignited and burned similarly to oil or other liquid fuel;

As changes of, construction could be made with-in-thescope of my invention, it is desiredthat al'lmatter'contained in the above description or shown in the accompanying drawing shall, be interpreted as illustrative" and not in a limitingsense.

Havingdescri'bed my invention, what If claim and desireto secure by Letters Patent 1. A fuel burner which comprises, a fuel' feedin passage-way having an annular outlet oriflce, means in said passageway for advancing fuel therethrough and through said outlet orifice, andmeans'for directing av jet of air radially outwardly across. the path of the fuel issuing from said orifice to break up and mix said fuel with said air.

2;. A fuel burner which comprises, a fuel; feeding passageway'having an annular out-. let orifice a screw conveyor in said'passageway" for forcing fuel therethrough and through said outlet" orifice, and means for supplying air under pressure through said screw conveyor and directing a jet of said air radially outwardly against the fuel issuing from said annular outlet orifice, to disintegrate said fuel and carry it in said air.

3. A fuel burner which comprises, a fuel feeding passage-way having an annular outlet orifice, a screw conveyor in said passage-way for forcing fuel therethrough and through said outlet orifice, means for supplying air under pressure through said screw conveyor and directing a jet of said air radially outwardly against the fuel issuing from said annular outlet orifice, to disintegrate said fuel and carry it suspended in said air, and means for introducing additional quantities of air into said commingled air and fuel and for directing said air and fuel mixture to a furnace.

4. A fuel burner which comprises, a fuel feeding passage-way, an air supply pipe extending through said passage-way, a support for said pipe at the outlet end of said passage-way and forming an annular outlet with the walls of said passage-way, a screw conveyor rotatably mounted on said pipe to force fuel through said orifice, a hollow cone spaced slightly from the outer face of said support to receive air from said pipe and direct it radially outwardly between its base and said support to intersect the fuel issuing through said annular orifice, and a nozzle mounted to receive the commingled air and fuel.

5. A fuel burner which comprises, a fuel conveyor tube, an air supply pipe extending through said tube, a support for said pipe at the outer end of said tube and forming an annular outlet orifice with the walls of said tube, means for conveying fuel through said tube and forcing it through said annular orifice, and means for receiving air from said pipe and directing it radially outwardly across the path of thefuel from said orifice.

6. A fuel burner which comprises, a fuel conveyor tube, an air supply pipe extending through said tube, a support for said pipe at the outer end of said tube and forming an annular outlet orifice with the walls of said tube, a screw conveyor rotatably mounted on said pipe to force fuel through said annular outlet orifice, a hollow cone mounted on the end of said pipe with its base spaced a short distance from said support to form a narrow jet passage intersecting the fuel from said annular orifice, said cone having passages to receive air from said pipe and direct it to said jet passage, and a nozzle member adapted to deflect the air and fuel from said jet and direct them to a furnace. V

7. A fuel burner which comprises, a fuel conveyor tube, an air supply pipe extending through said tube, a support for said it to said jet passage, a nozzle member positioned to deflect the air and fuel from said jet and direct them to a furnace and means for admitting aditional regulated quantities of air to said nozzle.

In testimony whereof, I affix my signature. v

EARL P. WETMORE. 

